The invention relates to a method for increasing the spontaneity in an automatic transmission in which the gear shifts are carried out as overlapping gear shifts. The overlapping gear shift comprises three phases. During the first phase the curve of a transmission input rotational speed is determined by the pressure curve of the first clutch, during the second phase the second clutch takes over the load from the first clutch and during the third phase the second clutch becomes completely closed.
In automatic transmissions, the gear shifts can be carried out as overlapping gear shifts, i.e. while a first clutch opens a second clutch closes. The pressure curve of the clutches involved in the gear shift is determined via electromagnetic actuators of an electronic transmission control. Such a control and regulation method has been disclosed, e.g. in DE-OS 42 40 621.
Gear shifts of the automatic transmission are usually initiated when a desired performance presettable by a driver, such as throttle valve position, exceeds an upshift or downshift characteristic line of a shift characteristic field. Together with the gear shifts triggered by means of accelerator pedal, a driver has the possibility at any desired moment of triggering manual gear shifts. For example, DE-OS 43 11 886 shows a device by which a driver can trigger gear shifts by means of a selector lever having a manual gate or switching levers on the steering wheel.
The following problem can now arise: during an overtaking operation the driver detects that he must give way to traffic coming from the opposite direction. As a reaction to this, he will interrupt the overtaking operation by releasing the accelerator pedal. Hereby an upshift can be triggered. During the upshift. if the driver now detects that the opposite lane is free, he will then again initiate the overtaking operation. For this purpose, the driver will either actuate the accelerator pedal or initiate a downshift via the selector lever. But according to the prior art, the automatic transmission will first completely carry out the upshift, followed by a blocking time and only then is a downshift begun. The problem thus consists in that a long time offset exists between the driver's wish relative to the acceleration and the reaction thereto of the automatic transmission.